Long-Term Analysis of Zygoma Implants

Oral Abstract Session 5: MAXILLOFACIAL RECONSTRUCTION The Use of the Buccal Fat Pad Flap for Reconstruction of Oral Defects: Report of the Mayo Clinic Experience Derek H. Lamb, DMD, Department of Surgery, Division of Oral and Maxillofacial Surgery, Mayo Clinic, 200 First Street, SW, Rochester, MN 55905 (Brisova L; Kademani D) Statement: The buccal fat pad (BFP) is a tri-lobed fatty structure surrounded by a thin fascial capsule located within the masticatory space. It is bordered medially by the buccinator muscle and laterally by the masseter muscle, ramus of the mandible and zygomatic arch. There are also four extensions that arise from the main body of the BFP, these are the buccal, temporal, pterygoid and pterygopalatine. The body and buccal extension make up the bulk (50-70%) of the fat pad and are situated more superficially, whereas the temporal, pterygoid, and pterygopalatine extensions tend to be smaller in volume and located deeper within the masticator and pterygopalatine space. The BFP has a rich vascular supply with contributions from the buccal and deep temporal branches of the maxillary artery, the transverse facial branch of the superficial temporal artery, and small branches of the facial artery. Its natural function is occupying the intermuscular area between the masseter, buccinator, temporalis and pterygoid muscles. The BFP assists muscular motion and contributes to the external morphology and shape of the face. The use of the buccal fat pad for intraoral reconstruction provides a simple, reliable and effective method for treating small to medium sized posteriorly based oral defects. Materials and Methods: We report our experience with 24 patients who underwent buccal fat pad transposition flap (BFPTF) reconstruction of 27 oral defects. Fourteen female and 10 male patients ranging in age from 22 to 81 years old were treated with the BFPTF in this study. Two patients had bilateral BFPTF. Seven (25%) of the BFPTF were used in the treatment of bisphosphonate associated osteonecrosis of the jaw, 6 (21%) in the reconstruction of postoperative squamous cell carcinoma defects, 4 (15%) for osteoradionecrosis of the mandible, 4 (15%) in the closure of oroantral fistulae following exodontia, and the remaining 6 (21%) for coverage of defects resulting from the treatment of various other pathologic conditions. The sites reconstructed using the BFPTF in the maxilla extended from the posterior maxilla and hard palate to the anterior alveolus. Other AAOMS • 2007

areas that were treated with the BFPTF are the retromolar trigone, buccal mucosa, and mandibular alveolus. Of the sites requiring reconstruction with the BFPTF 11 (33%) were located in the maxilla, 15 (46%) in the mandible, 3 (9%) involved the retromolar trigone, 2 (6%) were for buccal mucosal defects and 2 (6%) were for coverage of the hard palate. Three (13%) patients were smokers at the time of surgery. Four (17%) patients had undergone preoperative radiotherapy. Method of Data Analysis: A retrospective chart review was performed on all patients who underwent BFPTF reconstruction of various oral defects over a 3 year period from 2004 to 2007. All patients were required to have an adequate follow period ⬎3months for inclusion in the study. Results: Twenty four (89%) of the BFPTF healed without complication at 1 month with an overall success rate of 92.6%. There was a 4% rate of hematoma formation in the immediate postoperative period and a 7% rate of partial flap necrosis. No complete flap dehiscence was noted in the study group. Conclusion: The buccal fat pad transposition flap is a versatile pedicled flap for reconstruction of intraoral defects. The BFPTF is readily accessible and the technique for harvesting is simple and rapid without the addition of significant donor site morbidity. The BFPTF is ideally located for reconstruction of posterior oral cavity defects, however midline maxillary and mandibular defects can be safely approached using the BFPTF. Due to its utility, availability, and ease of use the BFPTF should be a part of the reconstructive armamentarium for small to medium sized oral cavity defects. References Samman N, Cheung LK, Tideman H. The buccal fat pad in oral reconstruction. Int J Oral Maxillofac Surg 1993; 22:2-6 Dean A, Alamillos F, Garcia-Lopez A, et al. The buccal fat pad flap in oral reconstruction. Head Neck 2001; 23:383-8 Amin MA, Bailey BMW, Swinson B, et al. Use of the buccal fat pad in the reconstruction and prosthetic rehabilitation of oncological maxillary defects. Br J Oral Maxillofac Surg 2005; 43:148-54

Long-Term Analysis of Zygoma Implants John Michael Ray, DDS, USS George Washington (CVN 73), Box 66, FPO, AE 09550-2873 (Parel SM; Triplett RG; Schow SR) Statement: The zygoma implant was introduced by Branemark in 1997 for patients in need of posterior implant support with the desire to eliminate bone grafting. Zygoma implants were originally intended for supporting fixed restoration of the completely edentulous 37.e1

Oral Abstract Session 5 maxilla but have since been used successfully in restoring the partially edentulous maxilla. The purpose of this study was to examine the long-term results of zygoma implants both in the completely and partially edentulous maxilla. Materials and Methods: The study includes 34 patients with a total of 65 fixtures placed. Excluded from the study were patients who did not have a final fixed prosthesis, those with fixtures placed less than 12 months ago and those lost to follow-up with less than 12 months total follow-up time. Method of Data Analysis: This study is a retrospective analysis of zygoma implants placed from 1999 to 2005. Data was collected from patient records, recall examinations and telephone interviews. Data collected for the study included age of the patient at time of zygoma implant placement, number and position of implant fixtures placed, intraoperative and postoperative complications, date of fixture loss, date of fixture replacement, loss of other conventional implant fixtures, type of provisional prosthesis, tobacco use and significant medical comorbidities. Results: Of the 65 zygoma implant fixtures placed, 8 were lost, yielding a success rate of 88%. Average follow-up time of the subjects was 46 months with a range of 15 to 86 months. Average age of the patient receiving the zygoma implants was 62 years, 8 months with a range of 28 years, 3 months to 83 years, 4 months. Conclusion: The results of this study confirm that the zygoma implant is a reliable method of providing fixed restoration of the atrophic posterior maxilla as an alternative to large bone grafts followed by conventional implants. As with any implant procedure, patient selection and careful attention to technique are important when considering this treatment option.

examined BMP-2 loaded NP-hydrogel complex lead enhanced bone formation in vivo. Materials and Methods: Eight-week-old Sprague-Dawley rats (n⫽48) was used. We created calvarial critical size defect (8 mm) with 1 mm round bur and 8 mm trephine bur and implanted four different transplants (the BMP-2 loaded nanoparticle-fibrin gel complex, BMP-2 loaded fibrin gel, nanoparticle-fibrin gel complex without BMP-2, bare fibrin gel). After 4 weeks, the animals were sacrificed and the skulls with defects were harvested. In vivo evaluation of bone formation was by soft X-ray, histology, immunostaining, and mineral content analysis, based on the rat calvarial critical size defect model. Analysis of bone generation was done by using one-way analysis of variance (ANOVA) test with Stat View II program (version 5.01). If significant diffence between groups was observed, a pairwise multiple test (Fisher’s PLSD) was used to compare all pairs of treatments. Differences were considered significant at p-vlalues less than 0.05. Method of Data Analysis: n/a Results: The effective bone regeneration was achieved by the BMP-2 loaded nanoparticle-fibrin gel complex, compared to bare fibrin gel, the nanoparticle-fibrin gel complex without BMP-2, or even the BMP-2 loaded fibrin gel in terms of the radiodensity, pattern of bone and functional marrow, the degree of osteocalcin expression, and the contents of calcium and phosphate in the regenerated bone area. The remodeling process of new bone developed by BMP-2 was significantly enhanced thus the mature and highly-mineralized bone was obtained by utilizing the functional nanoparticle-hydrogel complex. Conclusion: Nanoparticle-fibrin gel complex can be a promising candidate for a new bone defect replacement matrix and enhanced BMP-2 carrier.

References Bedrosian, et al. The Zygomatic Implant: Preliminary Data, IJOMI, 2002, 17 (6):861-865 Schow SR and Parel SM. The Zygoma Implant in Peterson’s Principles of Oral and Maxillofacial Surgery, BC Decker, 2004

Enhanced Bone Regeneration With BMP2 Loaded Functional NanoparticleHydrogel Complex Kang-Mi Pang, DDS, Seoul National University Dental Hospital, 275-1 Yeongeon-Dong, Jongno-Gu, Seoul, Korea (Jeon SH; Lee JY; Kim YD; Ahn KM; Lee SY; Chung YI; Tae G; Lee JH) Statement: For the sustained and enhanced bone formation of BMP-2, functional nanoparticle-hydrogel complex which is composed with the heparin, functionalized nanoparticle and fibrin gel, was developed. In this study, we evaluate the role of heparin whether it could sustain the release of bioactive BMP-2 in vitro. We also 37.e2

References Byung Ho Woo et al. Enhancement of bone growth by sustained delivery of rhBMP-2 in a polymeric matrix, Pharmaceutical reserch, Vol 18, No 12, Dec 2001 Liu Y et al. BMP-2 liberated from biomimetic implant coatings induces and sustains direct ossification in an ectopic rat model, Bone, Vol 36, No 5, May, 2005

Reconstruction of the Canine Mandible Using a Custom Made Bioabsorbable uHA/PLLA Mesh Tray With PCBM and PRP Akira Matsuo, DDS, PhD, 6-7-1 Nishishinjuku Shinjukuku, Tokyo, 160-0023, Japan (Chiba H; Takahashi H; Shikinami Y) Statement: Mandibular reconstruction is one of the most challenging fields in oral and maxillofacial surgery. Particulate cancellous bone and marrow (PCBM) combined with platelet rich plasma (PRP) is highly effective AAOMS • 2007